Speed Planning For Solar-Powered Electric Vehicles

With the development of economic,human demand for energy is growing.It consumes a lot of fossil fuels not only leads to the shortage of energy,but also causes serious environmental pollution.Car ownership in the world in the past 15 years has increased to about 1 billion,which is twice the original ownership.Its energy consumption accounts for more than half of the world's oil sales,which is one of the most important reasons for energy shortage and environmental pollution.In order to alleviate the energy crisis,improve the living environment,electric vehicles gradually come into people's lives.EVs use renewable energy sources such as solar energy,wind energy,hydro energy,etc.,which can effectively solve the problem of energy crisis.Furthermore,EVs can also improve the living environment,because of the use of electricity which can avoid the harmful gases spreading into the atmosphere(zero emission).EVs will inevitably become the development trend of the future transportation.But there are still some problems such as the short driving range,poor availability of charging stations and long charging time.The solar-powered EVs are the combination of solar cells and EVs.Solar-powered EVs,which mostly rely on solar energy,are free of charging limitations.However,the range anxiety problem is more severe due to the availability of sun light.For example,shadings of buildings or trees may cause a solar-powered EV to stop halfway in a trip.In this thesis,the main content is to optimize the speed on different road segments so that to balance energy harvesting and consumption,which can enable a solar-powered EV to reach the destination using the shortest travel time.The speed planning problem is essentially a constrained non-linear programming problem,which is difficult to solve.We have identified an optimality property that allows us to compute an optimal speed assignment for a partition of the path.Then,a dynamic programming method is proposed to efficiently compute the optimal speed assignment for the whole trip with significantly low computation overhead compared to the state-of-the-art non-linear programming solver.